std::set::size

 

C++

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概念

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容器库

array （C++11）

vector

deque

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list

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std::set

成员函数 Original: Member functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

set::set

set::~set

set::operator=

set::get_allocator

迭代器 Original: Iterators The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

set::begin set::cbegin （C++11）

set::end set::cend （C++11）

set::rbegin set::crbegin （C++11）

set::rend set::crend （C++11）

容量 Original: Capacity The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

set::empty

set::size

set::max_size

修饰符 Original: Modifiers The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

set::clear

set::insert

set::emplace （C++11）

set::emplace_hint （C++11）

set::erase

set::swap

查找 Original: Lookup The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

set::count

set::find

set::equal_range

set::lower_bound

set::upper_bound

观察员 Original: Observers The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

set::key_comp

set::value_comp

 

size_type size() const;

Returns the number of elements in the container, i.e. std::distance(begin(), end()).

参数

（无）

Original:

(none)

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返回值

在容器中的元素的数量

Original:

the number of elements in the container

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例外

noexcept specification:  

noexcept

  （C++11 起）

复杂性

Constant

为例

The following code uses size to display the number of elements in a std::set<int>:

#include <set>
#include <iostream>
 
int main()
{
    std::set<int> nums {1, 3, 5, 7};
 
    std::cout << "nums contains " << nums.size() << " elements.\n";
}

Output:

nums contains 4 elements.

另请参阅

empty	检查是否容器是空的 Original: checks whether the container is empty The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
max_size	返回可能的最大数量的元素 Original: returns the maximum possible number of elements The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）